Corri,
I may (must) be misunderstanding your post. I agree that I am responsible for my own hapiness. However, when in a comitted relationship, the actions for my partner affect me. If I am not happy about one of my partner's actions, tell my partner as such and yet the action (or lack of action ) keeps occuring - then what? The only solution then is to get rid of the relationship. Isn't it?
The only other way I can think of is to indeed change yourself so that the action in question doesn't make you unhappy anymore. Sometimes that's just not possible, especially if that action violates your own sense of morals/ethics, etc.

Sorry that I am not as eloquent as some of ya'll. Hopefully ya got my meaning.

The differentiation song: All I want to do Is be more like me And be less like you Linkin Park